Reloading for the 7.62x38mmR Nagant Revolver, Part 1

I finally got around to ordering a set of Lee 7.62x38R dies for my Nagant Revolver from Graf & Sons, as you can see above. You can get these dies from all the usual sources- Midway has them at a similar price- but Graf had the appropriate bullets and the cases I needed in stock, so that's where I ordered from. This set is unusual for Lee, as it's the only die set they sell that doesn't come with any reloading data. For some reason there's a powder measure scoop included even though there's no data go with it. Even more curiously, the scoop is large- too large for any powder charge I know of for the 7.62x38R.

The set isn't designed for use with the the factory 7.62x38R case. Instead, it's intended to convert .32-20 cases into a sizethat will chamber properly in the Nagant revolver. To that end, only the recapping/resizing die is specifically designed for the Nagant revolver; the expander and seating-crimping die are actually .32-20 dies, as you can see:

I also obtained a hundred plated 98grain double-ended wadcutter bullets that resemble the Russian factory loaded bullets in profile:

The original bullet in the Soviet service round was a steel-cored jacketed bullet. These are impossible to find, and wouldn't be a good choice for someone trying to make an accurate round in any case. There are plenty of jacketed bullets around but using a jacketed bullet pushes the pressure up, not something desirable when developing a load for a gun for which there isn't a lot of data. Soft lead bullets keep the pressure down, and plated bullets are generally self lubricating.

Since I didn't have any .32-20s on hand, I ordered 200 Starline .32-20 unprimed cases. The choice of case is important here; most .32-20 cases are just a few thousandths too thick to work properly in a Nagant revolver, and either the gun or the cases have to be modified. Starline makes the rim on theirs just a bit thinner so that they function in the Nagant and still work in older .32-30 guns.

The .32-20 is a a bottlenecked case that was introduced in 1885 as a small and medium sized game cartridge. To allow it to chamber in the Nagant, all that's required is one pass through the sizing die, as you can see:

For primers I'll be using standard small Winchester primers, as I have plenty on hand. Choice of powder is the final, and perhaps most critical choice. Since the .32-20 based reload doesn't seal the cylinder/barrel gap like the factory load does, it's a good idea to use a fast burning powder to minimize fouling and maximize efficiency. Some reloaders have experimented with small (1.5-2.0) grains of Bullseye, but using very small amounts of powder in a large case can lead to erratic ignition. Luckily there's a powder that burns as fast as Bullseye but is much bulkier: IMR Trail Boss:

A number of reloaders have suggested 3.5 grains of Trail Boss as a good load for the 7.62x38R. Tables for similar cartridges suggest this will generate pressures under 16,000 CUP, and that's very close to the  working pressure of the Soviet military load, according to a few sources. I'll probably start with something like 3.2gr and work my way up to that. I also intend to experiment with other soft lead bullets. A lot of reloaders are using lead round nose bullets designed for the .32 S&W.

Click here for Part 2